Thermoelectric motor



Patented May 17, 1932 UNITED srpfrns Perm* oFFlcE GEORGE yP. LEWIS, F FOREST HILLS, AND RAYMOND E. SABIN, OIF FLUSHING, NEW YORK THERMOELECTRIC MOTOR Application filed September 19, 1930. Serial No. 482,924.

The object of this invention is to provide a. thermo-electric motor of simple and efficient construction and operation whereby a steady and deliberate motion, within definite limits, is imparted to a movable member',

such, for example, as the oscillatory arm of a display or advertising apparatus.

To this end our invention, generally stated, comprises, in a thermo-electric motor, a thermal element included in an electric circuit; a movable member operatively connected with said element, and means also included in the circuit for intermittently making and breaking the circuit to effect and permit the l5 alternate expansion and contraction of the thermal element.

vMore specifically stated, our invention coinprises, in a thermo-electric motor, a thermal element included in an electric circuit and 2G embodying a filament of expansible and contractible resistant material, such as nichrome; a fixed support to which the ends of the filament are connected; a vibratory support for succeeding loops of the filament; a spring connected with said vibratory support and acting thereon to maintain the filament under constant tension; a rock-arm operatively connected with the vibratory support; a make and break switch also included in the electric circuit; and connections between said switch and the rock-arm.

The invention also comprises novel features of construction and combinations of parts which will be hereinafter described; the scope of the invention then being defined in the appended claims.

In the drawings- Figure 1 is a longitudinal Vertical section of a thermo-electric motor embodying the principle of our invention.

Fig. 2 is a left hand end elevation of the motor. l

Fig. 3 is an elevation of the opposite end thereof.

Fig. 4 is a plan of the apparatus.

Fig. 5 is a bottom view of the same.

Referring to the drawings, 10 designates a suitable supporting structure comprising an elongated vented casing, preferably composed'of a foraminated sheet of'metal bent to provide a top 11 and sides 12. Between the sides, adjacent one end of the casing, is affixed a supporting piece 13 to the outer face of which is secured a block 14 of insulating material, and also between the sides adjacent the opposite end of the casing is a lever member 15 to the outer face of which is secured a block 16 of insulating material. Preferably the lever 15 is affixed to a pivot rod 17 having its bearings in the sides of the casing, lubricating washers a being mounted on the rod adjacent the respective sides. The lower ends of the blocls 14, 16 are provided with correspondingly spaced hooks 18; and a wire 19 of expansible and contractible resistant material, such as nichrome, is secured at one end to one of the outermost hooks of the block 14 and drawn thence longitudinally under tension to and about the corresponding hook of the block 16; thence to and about the second hook of the block 14, and thence from hook to hool?` of the respective blocks in succession until the final hook of the block 14 is reached, whereupon the free end of the wire is secured to the last-named hook.

In the present instance the wire is provided at its extremities with eyes 20 which are conveniently applied to the respective outermost hooks of the block 14. In this way is provided a continuous thermal element of great length and correspondingly large crosssection to insure adequate strength for its intended purpose, yet occupy comparatively small compass.

This thermal element is included in an electric circuit, and hence if the circuit be intermittently made and broken the wire 19 will expand and contract accordingly. In the present instance the end hooks of the block 14 are electrically connected to bridge straps 21, 22 which, in turn, are connected to terminals 23, 24, respectively, on the block 14, the terminal 23 being one of the terminals` of a condenser 25, which is mounted on such block. The other terminal of the condenser is indicated at 26. rllhe lead wires 27 of the electric circuit are connected to the terminals 24, 26, and the latter terminals and the terminal 23 are electrically connected, as by wires 28, to a suitable electric switch positioned on the casing. This switch is adapted to make and break the circuit in a manner to effect and permit the alternate heating and cooling of the resistance wire 19 as hereinafter described. The function of the condenser is to absorb the spark at the switch gap when the circuit isbroken.

The resistance wire is held resiliently under tension by means of a retracting spring 29 whereof one end is secured to a cross-pin 3Qin .the casing andthe otherend to a link.

31 which is pivotally attached to the upper end of the lever 15. The inner end ofthe link 31 is formed with la. longitudinal guide slot 32 through which freely extends a pin or stud 33 on an up-standing rock-arm 34.

Preferablythis -arm isaiixed to a pivot rod 35 having` its bearings Yin the sides of the casing,.'lubricatingwashers b being mounted on therod'ladjacent the respective sides. The arinw34, extends through and above an openin`v in the top of the casing. A relatively7 ligA tvspring 36 Secured to the arm 34 and the top of the casing tends to maintain the arm inclined at one side of vthevertical and with the stud 33 in contact withthe opposing end of the slot 32 of the link when the wire 19 is contacted against thetension of the spring 29. A suitably disposed cross-rod 37 in the casing serves as a positive back stop for the arm.

By= this construction itwill be seen that when the resistance wire is contracted the spring 29 is held under tension, thus drawing thelink and exerting through the lever 15...:'1 considerable pull on the wire, in which case the arm 34, by virtue of its pin and slot connection with the link isheld in inclined'.

position by the action of the spring 36, as indicated in full lines in Fig. 1. It rwill also be seen that as and when the wire is expanded by heatthe retractive force of the spring on the link pullsthe arm to the position indicated by thel dotted lines in Fig. 1.

The particular illustrative form of switch herein shown comprises alfixed base 38 of insulating material havinga plate 39 provided with arcontact point 390, to which plate one of the wires 28 from thel Condenser is connected; and also comprises a vibratory contact arm 40 having lateral upstanding lugs 41 which are pivoted on'the inturned ends 42 of an upstanding yoke lever 43, which ends are, in turn, pivoted in the spaced side y members 44 of a U-bracket fixed on the base.

One `end of the contact arm is electrically connected by means of a wire 45 with the terminal` 45,0v ofthe other lead wire 28 .from the condenser. The f other end of the arm 40 A. is provided with a contact point 46 which by` actuationof the arm is moved into and out ot contact with the point 390, thus respec tively making and breaking the electric cir-4 cuit. 4The upper member of the yoke lever 43- is pivotally connected bymeans of a link 47 with the rock-arm 34, which link thus transmit the motion from the rock-arm to the yoke lever.

A spring 48 is secured at its upper end to a cross-rod 49 on the yoke lever, and at its lower end to a lug 50 on the contact arm 40, which lug is so disposed that when the lever 43 is swung in one direction the spring 48 is positioned beyond one side of the axis of the lugs 41, thus tending to lift the rear end and depress theforward orcontact end of the arm 40, thereby completing the circuit, but when the lever 43 is swung in the opposite direction the spring 48 is swung toward and beyond such axis, thus partially turning the contact arm about the axis and perforce lift ing the contact point 46 in a manner to break the circuit, as indicated by the dotted lines in Fig. 1.

' The foregoing described construction affords a simple, inexpensive and reliable thernio-electric motor whereby a steady and de liberate motion of relatively wide range is imparted to an actuating element through the medium of an electric current whereof the circuit includes an expansible and contractible resistor and also means for alternately making and breaking the circuit in synchronism with the motion of the actuating element. While the invention is particularly applicable for use in connection with mechanical dis! play or advertising devices, it is to be understood that it is not llimited to use in that particular relation.

It is to be understood also, that the invention is not limited to the details of construe: tion herein disclosed, as the structure illus# trated maybe variously modified within the principle of our invention and the scope ov the appended claims.

We claimy 1. In a thermo-electric motor, the combination with asupport, oiE a movable actuat ing elementthereon, a lever, a vconnection between said element and lever, an vexpansible element consisting of a resistance wire connected with the lever and included in an electric circuit, means for resiliently acting` on said lever `to maintain the wire under ten! sion, an electric switch alsoincluded in the` circuit, and operative connection between the said actuating element and the switch.

2. In a thermo-electric motor, the combination with'a support, of a movable actuating A element thereon, a lever member, a fixed mem-i ber spaced from the lever member, a connection between said level-*member and the am. tuating element, an expansible element consisting of a resistance wire secured at its ends to for intermittently making and breaking the electric circuit.

3. In a thermo-electric motor, the combination with a support, of a movable actuating 6 element thereon, a lever member, a fixed member spaced from the lever member, a connection between said lever member and the actuating element, an expansible element consisting of a resistance wire secured at its ends 1o to the fixed member and looped back and forth between said member and the lever member, said wire included in an electric circuit, resilient means acting on said lever member to maintain the wire under tension, an electric N5 switch also included in the circuit, and means connecting the actuating element and the switch.

4. In a thermo-electric motor, the combination with a support, of an oscillatory actuating arm supported thereby, a lever member,

a lixed member spaced from the lever member, a link connection between said lever member and the oscillatory arm, a retracting spring for said link, an expansible element consisting of a resistance wire connecting the fixed member and the lever member, said wire included in an electric circuit, and means for intermittently making and breaking the y electric circuit.

80 5. In a thermo-electric motor, the combination with a support, of an oscillatory actuating arm supported thereby, a lever member, a fixed member spaced from the lever member, a link connection between said lever mem- 85 ber and the oscillatory arm, a retracting spring for said link, an expansible element consisting of a resistance wire connecting the fixed member and the lever member, said wire included in an electric circuit, an electric switch also included in the circuit, and means connecting the actuating element and the switch.

6. In a thermo-electric motor, the combination with a support, of an oscillatory actuating arm supported thereby, a relatively light retracting spring for said arm, a lever member, a fixed member spaced from the lever member, a link between said lever member and oscillatory arm, said link having a pin and slot connection with the arm, a relatively strong spring for said link acting in opposition to the first-named spring, an expansible element consisting of a resistance wire connecting the fixed member and the lever member, said wire included in an electric circuit,

an electric switch also included in said circuit, and means connecting the actuating arm and the switch.

Signed at New York in the county and G0 State of New York this 2d day of September, A. D. 1930.

GEORGE P. LEWIS. RAYMOND E. SABIN. 

